Camera module and light blocking layer forming method thereof

ABSTRACT

A camera module according to exemplary embodiments of the present disclosure includes a lens holder configured to support a plurality of sheets of lenses, an actuator configured to be arranged at an upper surface of the lens holder, an outermost lens configured to move along an optical axis by the actuator, and a light blocking layer configured to be positioned on a surface of the outermost lens.

This application is a Continuation Application of U.S. application Ser.No. 14/098,144, filed Dec. 5, 2013, which claims the benefit of theearlier filing date and right of priority to Korean Patent ApplicationNo. 10-2012-0141204, filed on Dec. 6, 2012, under 35 U.S.C.§119 (a), thecontents of which are hereby incorporated by reference in theirentirety.

BACKGROUND OF THE DISCLOSURE

1. Field

The teachings in accordance with the exemplary embodiments of thispresent disclosure generally relate to a camera module and a lightblocking layer forming method of the camera module.

2. Background

Recently, demand on small-sized camera modules is high as image inputdevices for various multimedia fields such as tablet computers, cameraphones, PDAs (Personal Digital Assistants), smart phones, toys,monitoring cameras and video tape recorders. Particularly, the smartphones require small-sized camera modules in response to increaseddemand by consumers preferring miniaturized designs.

The camera module is generally manufactured using an image sensor chipor a photoelectric conversion device of a CCD (Charge Coupled Device)type or a CMOS (Complementary Metal Oxide Semiconductor) type toconverge light from an object to a photosensitive element through a lensand to form an image of the object on a display medium such as an LCD(Liquid Crystal Display) display device.

SUMMARY

An object of the present disclosure is to provide a camera moduleintegrally formed with a light blocking layer to allow forming anaperture on an outermost lens of an auto focusing unit using lensmovement or on a moving lens.

In order to achieve at least the above object, in whole or in part, andin accordance with the purposes of the disclosure, as embodied andbroadly described, and in one general aspect of the present disclosure,there is provided a camera module, the camera module comprising:

a lens holder configured to support a plurality of sheets of lenses;

an actuator configured to be arranged at an upper surface of the lensholder;

an outermost lens configured to move along an optical axis by theactuator; and

a light blocking layer configured to be positioned on a surface of theoutermost lens.

Preferably, but not necessarily, the light blocking layer may be formedby any one method of painting or stamping on the surface of theoutermost lens.

Preferably, but not necessarily, the light blocking layer may bepositioned on at least one of an exposed surface of the outermost lensand a non-exposed floor surface opposite to the lens.

Preferably, but not necessarily, a holder cover may be interposedbetween the lens holder and the actuator.

Preferably, but not necessarily, the holder cover may be conductiblyconnected to the actuator.

Preferably, but not necessarily, the light blocking layer may take ashape of a disc centrally formed with a through hole.

Preferably, but not necessarily, the actuator may be any one of a microactuator, a liquid crystal lens, a piezoelectric polymer lens, anon-MEMS (Micro Electro Mechanical System) actuator, a MEMS actuator, asilicon type actuator and a liquid lens.

In another general aspect of the present disclosure, there is provided alight blocking layer forming method of a camera module, the methodcomprising:

forming a light blocking stamping surface on a substrate;

contacting a master mold formed with a ring-shaped lug to the lightblocking stamping surface;

forming a light blocking layer by transcribing the light blocking layeron the lug using a surface energy difference; and

forming the ring-shaped light blocking layer on an exposed outermostlens surface by contacting the ring-shaped light blocking layertranscribed on the lug to an outermost lens surface activated by anactuator and by transcribing the light blocking layer to the outermostlens surface using a surface energy difference.

Preferably, but not necessarily, the step of transcribing the lightblocking layer may include aligning a center of the outermost lens to acenter of the ring-shape lug.

Preferably, but not necessarily, the step of transcribing the lightblocking layer may include aligning a distal end of the ring-shaped lugto a periphery of the outermost lens by forming a diameter of thering-shaped lug corresponding to a diameter of the outermost lens.

Preferably, but not necessarily, the step of transcribing the lightblocking layer to the outermost lens surface may include transcribingthe light blocking layer to an exposed upper surface of the outermostlens.

Preferably, but not necessarily, the step of transcribing the lightblocking layer to the outermost lens surface may include transcribingthe light blocking layer to an exposed surface of the outermost lens.

The present disclosure has an advantageous effect in that an outermostlens moving for auto focusing function is formed with an aperture usinga light blocking layer to simplify a manufacturing process therebydispensing with inconvenience of forming an aperture using a separatefilm member.

Another advantageous effect is that a lens weight can be reducedcompared with a lens using a conventional light blocking layer tothereby improve a response characteristic of an auto focusing unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the disclosure andtogether with the description serve to explain the principle of thedisclosure. In the drawings:

FIG. 1 is a schematic cross-sectional view illustrating a camera moduleaccording to an exemplary embodiment of the present invention; and

FIGS. 2 to 6 are schematic views illustrating a method of forming alight blocking layer on an outermost lens according to an exemplaryembodiment of the present invention.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiment of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic cross-sectional view illustrating a camera moduleaccording to an exemplary embodiment of the present invention, and FIGS.2 to 6 are schematic views illustrating a method of forming a lightblocking layer on an outermost lens according to an exemplary embodimentof the present invention.

Referring to FIGS. 1 to 6, a camera module includes an auto focusingunit using a lens movement, and may further include a lens holder (10),at least one sheet of lens (20), a holder cover (30), an actuator (40)and a light blocking layer (100).

The lens holder (10) may be installed therein with at least one sheet oflens (20), each lens (20) having a different diameter and a shape. Thelens holder (10) may be injection-molded using a resin material, andapproximately take a shape of a cylinder. Although the lens holder (10)may take a shape of a circular cylinder according to configuration of acamera module, the present disclosure is not limited thereto, and thelens holder (10) may take a shape of a multi-angled pillar, adual-angled cylinder and a triple-angled cylinder.

Meantime, the lens (20) may be formed with a lens group consisting ofdifferent shapes of lenses, where each lens may be overlapped at acenter. Albeit not being illustrated, optical parts such as shutters andapertures may be separately installed.

The holder cover (30) may function to close an opening at an upper sideof the lens holder (10) and prevents the lenses (20) from being exposedto outside. The holder cover (30) may be installed at an upper side witha lens-moving type actuator (40). To this end, the holder cover (30) maybe conductively connected to the activator (40). For example, a separatewired connection member such as CF-PCB may be provided, and anelectronic circuit pattern layer may be provided on a surface of theholder cover (30), the lens holder (10) or the lens (30). The holdercover (30) may be centrally formed with a through hole, where a diameterof the through hole may be greater than that of an outermost lens (41,described later).

The technology of forming an electronic circuit pattern layer on thesurface may be largely classified into three methods.

-   -   First, a first method is a patterning method through an        over-molding which is a process that is used in manufacturing        forms to create parts and improve product efficiency. That is,        the over-molding or two-shot molding is an injection molding        process using two separate molds of which one material is molded        over another material. In this case, a part forming the lens        (20) is used with one material and a part forming the electronic        circuit pattern layer is used with another material, where two        parts are injection-molded.    -   In this case, the lens (20) is molded with an insulating        material while the electronic circuit pattern layer is molded        using a conductive synthetic resin. Alternatively, a part to be        formed with the electronic circuit pattern layer is molded using        synthetic resin capable of being easily metal-plated, the lens        (20) is injection-molded, to finish the electronic circuit        pattern layer using a post-processing such as a plating process.    -   A second method is such that, the lens (20) is injection-molded        while containing impurities reacting to light and heat, the        injection-molded lens (20) is formed with a wiring pattern where        the electronic circuit pattern layer is to be formed, using        surface patterning work such as laser exposure. When the        electronic circuit pattern layer is formed using the        abovementioned method, an SMD (Surface-Mount Device) or        accessory electronic parts can be directly mounted because the        electronic circuit pattern layer itself has a conductible        property.    -   A third method is a method allowing formation of a 3-D PCB on an        injection-molded substrate using fine-pitch laser patterning,        giving excellent thermal and electrical properties. In this        case, a front is metalized, and a non-circuit part is etched and        patterned. To be more specific, an entire surface of the lens        (20) is metalized, where only a part forming the electronic        circuit pattern layer is left untouched, and balance is etched        to integrally form the electronic circuit pattern layer on the        surface of the lens (20).    -   Referring to FIG. 1, when an electronic circuit pattern layer is        formed on the surface of the lens (20), there is no need of        installing a separate conductive connection member, and the        actuator (40) and a distal end of an image sensor can be        directly connected, using the electronic circuit pattern layer        formed on the surface of the lens (20) and distal ends (not        shown) formed at both ends of the electronic circuit pattern        layer, whereby a mounting space for parts installation can be        advantageously reduced when miniaturized electronic parts are        assembled, and assembly process can be simplified.

The actuator (40) may vertically move one sheet of the outermost lens(41) relative to an optical axis, or may adjust a focus of an image bychanging a shape of the outermost lens (41) and changing a refractiveindex of light passing through the outermost lens (41). The actuator maybe any one of a micro actuator, a liquid crystal lens, a piezoelectricpolymer lens, a non-MEMS (Micro Electro Mechanical System) actuator, aMEMS actuator, a silicon type actuator and a liquid lens. However, thepresent disclosure is not limited thereto, and an actuator of MEMS typemay be also used.

The light blocking layer (100) may be formed with a material that doesnot pass light to an exposed surface of the outermost lens (41). At thistime, the light blocking layer (100) may be formed by using a surfaceenergy difference such as stamping or painting method, dispensing with aseparate film material.

That is, as illustrated in FIG. 2, a light blocking stamping surface(200) is formed on a surface of a substrate (50) and a predeterminedmaster mold (60) may be contacted to the light blocking stamping surface(200). At this time, a surface opposite to the substrate (50) of themaster mold (60) may be formed with a ring-shaped lug (61) where adistal cross-section of the lug (61) may contact the light blockingstamping surface (200) coated on the surface of the substrate (50) asillustrated in FIG. 3.

Referring to FIG. 4, when the lug (61) is brought into contact with thelight blocking stamping surface (200), the light blocking layer (100)separated from the light blocking stamping surface (200) may be moved ina ring shape to each distal cross-sectional surface of the lug (61).Referring to FIG. 5, the moved light blocking layer (100) may move themaster mold (60) to an upper surface side of the outermost lens (41) toallow a distal end of the lug (61) formed with the light blocking layer(100) to contact an upper surface of the outermost lens (41), wherebythe light blocking layer (100) can be moved to an exposed surface of theoutermost lens (41) like an act of stamping. Then, as illustrated inFIGS. 1 to 6, the light blocking layer (100) is transcribed and attachedto the upper surface of the outermost lens (41).

The configuration thus described above can improve a response of theactuator that uses movement of a single lens, because the weight of theoutermost lens can be reduced over a configuration of a light blockingfilm being attached on a surface of a conventional lens. Particularly,the configuration thus described above can greatly improve performanceof a structure where a lens weight has a great influence on responsecharacteristics and reliability.

That is, an aperture can be integrally formed on an outermost lens of anauto focusing unit using lens movement or on a moving lens according toexemplary embodiments of the present disclosure.

Furthermore, a process of storing and transporting a light blocking filmafter the light blocking film is formed using a fine process, and aprocess of attaching the film to a lens surface can be omitted tothereby improve an operational accuracy and reduce the number ofprocesses.

Still furthermore, there is an advantageous aspect in terms ofoperational accuracy and automation, because a center of the master mold(60) and a center of the outermost lens (41) are aligned and mutuallycontacted to form the light blocking layer (100) according to theexemplary embodiments of the present disclosure, although there is ahigh probability of generating a defect to lens due to existence ofmechanical tolerances, when a film is attached while a center of athrough hole centrally formed at a light blocking member and a center ofa lens are accurately matched and, when a light blocking member isformed using a separate member such as a film.

The previous description of the present disclosure is provided to enableany person skilled in the art to make or use the inventive disclosure.Various modifications to the disclosure will be readily apparent tothose skilled in the art, and the generic principles defined herein maybe applied to other variations without departing from the spirit orscope of the disclosure. Thus, the present disclosure is not intended tolimit the examples described herein, but is to be accorded the widestscope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A camera module, comprising: a lens holderconfigured to support a plurality of sheets of lenses; an actuatordisposed on an upper portion of the lens holder; an outermost lensconfigured to be controlled by the actuator; and a light blocking layerconfigured to be positioned on a surface of the outermost lens, whereinthe actuator is configured to adjust a focus of an image by changing ashape of the outermost lens.
 2. The camera module of claim 1, whereinthe light blocking layer is formed by any one method of painting orstamping on the surface of the outermost lens.
 3. The camera module ofclaim 1, wherein the light blocking layer is positioned on at least oneof an exposed surface of the outermost lens and a non-exposed floorsurface opposite to the lens.
 4. The camera module of claim 1, wherein aholder cover is interposed between the lens holder and the actuator. 5.The camera module of claim 4, wherein the holder cover is conductiblyconnected to the actuator.
 6. The camera module of claim 1, wherein thelight blocking layer takes a shape of a disc centrally formed with athrough hole.
 7. The camera module of claim 1, wherein the actuator isany one of a micro actuator, a liquid crystal lens, a piezoelectricpolymer lens, a non-MEMS (Micro Electro Mechanical System) actuator, aMEMS actuator, a silicon type actuator and a liquid lens.
 8. The cameramodule of claim 1, further comprising an electronic circuit patternformed on any one of the outermost lens and the lens holder.
 9. Thecamera module of claim 8, wherein the electronic circuit pattern isformed on a surface of any one of the outermost lens and the lensholder.
 10. The camera module of claim 8, further comprising an imagesensor, wherein the actuator is electrically connected to the imagesensor.
 11. The camera module of claim 1, further comprising an imagesensor, wherein the actuator is electrically connected to the imagesensor by a connection member.
 12. The camera module of claim 1, whereinthe actuator is a piezoelectric polymer lens.
 13. The camera module ofclaim 12, wherein a focus of an image is adjusted by changing arefraction of light passing through the outermost lens.
 14. The cameramodule of claim 11, wherein the actuator is a piezoelectric polymerlens.
 15. The camera module of claim 14, wherein a focus of an image isadjusted by changing a refraction of light passing through the outermostlens.
 16. The camera module of claim 11, wherein the connection memberis a printed circuit board.
 17. A camera module, comprising: a lens; alens holder supporting the lens; an actuator disposed on an upperportion of the lens holder and including an outermost lens; and a lightblocking layer configured to be positioned on a surface of the outermostlens, wherein the actuator is configured to adjust a focus of an imageby changing a shape of the outermost lens.
 18. The camera module ofclaim 17, wherein the actuator is a piezoelectric polymer lens.
 19. Thecamera module of claim 17, wherein a focus of an image is adjusted bychanging a refraction of light passing through the outermost lens. 20.The camera module of claim 17, further comprising an image sensor,wherein the actuator is electrically connected to the image sensor by aconnection member.